Apparently YES! The skull ridge will stop even a mid-caliber round, like a .380 or 9mm, the chest has too many thick muscles, so I am seeing in reading about such attacks, that the nose is a effective path to the brain, and a round that enters through the front of the snout reaches the brain, and, well, lights out....
Of course that's the theory. I can't imagine having the nerve or skill to be able to hit such a target under stressful conditions; but then again I'm not a person that puts myself in such situations.
Handguns have proven to be very effective.
Even some so called smaller calibers.
Read the article at the link and have better information.
https://www.ammoland.com/2021/06/handgun-or-pistol-against-bear-attacks-104-cases-97-effective/